S100A9 and myelodysplastic syndrome: Increased expression of danger-associated molecular pattern (DAMP) molecules S100A8/S100A9 in MDS patients perpetuates noninfectious inflammatory responses that result in the accumulation of Lin- HLA-DR- CD33+ myeloid-derived suppressor cells (MDSCs) in the BM (Chen et al., 2013; Cluzeau et al., 2017; Cheng et al., 2019).